A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

What is the value of a? 9a - 3(a - 6)= -6 a=?

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @mathstudent55

  2. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    In this equation, you first need to simplify the expression and get rid of parentheses.

  3. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You need to use the distributive property on the left side.

  4. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443652798689:dw|

  5. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The first step in this equation is to simplify -3(a - 6) using the distributive property

  6. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443652952295:dw|

  7. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I copied the 9a and the = -6 to the next line. We are only going to work on what is in the box. |dw:1443653017673:dw|

  8. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443653089656:dw|

  9. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    That was just applying the distributive property. Now we simplify -3(-6) What is (-3) * (-6) = ?

  10. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    18?

  11. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Correct, since negative times negative is positive.

  12. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443653260886:dw|

  13. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    We simplified the parentheses. Now we need to combine like terms on the left side. We need to combine the 9a and -3a terms. What is 9a - 3a = ?

  14. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    3a^2?

  15. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    No. The exponent only changes when you multiply variables. Think of a as some unknown thing. It can be the number of books on a shelf, only you don't know it. If I ask you "there are 9 books and I took away 3 books, how many books are left?" What is the answer?

  16. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    6

  17. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    9 books - 3 books = 6 books 9 bananas - 3 bananas = 6 bananas 9 shirts - 3 shirts = 6 shirts 9a - 3a = 6a

  18. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You must keep the "a". 9 - 3 = 6 (no numbers here have "a".) 9a - 3a = 6a If you have 9 "a's" and you take away 3 "a's" you are left with 6 "a's"

  19. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443653672095:dw|

  20. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Ok so far?

  21. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  22. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Now we have an equation similar tot eh two we saw before. We need to undo the addition of 18 by subtracting 18 from both sides. |dw:1443653770531:dw|

  23. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Since nothing is being added to or subtracted from 6a, we just copy the 6a down. What is 18 - 18 ?

  24. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    0

  25. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443653854679:dw|

  26. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Good. What is -6 - 18?

  27. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -24

  28. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Correct. We have: |dw:1443654066983:dw|

  29. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    "a" is being multiplied by 6. We want "a" by itself on the left side. Now can you tell what we still need to do to get "a" by itself?

  30. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    subtract it by itself?

  31. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @mathstudent55

  32. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    a is being multiplied by 6. To undo a multiplication, you need to do the opposite operation. What is the opposite operation to a multiplication?

  33. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    division

  34. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Correct. Since "a" is being multiplied by 6, you need to divide it by 6. Since we need to do the same to both sides of an equation, we divide both sides of the equation by 6.

  35. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1443654727026:dw|

  36. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    What is -24/6 ?

  37. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -4

  38. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and 6/6 is 1

  39. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Correct & correct. We have: |dw:1443655009021:dw|

  40. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The solution is a = -4

  41. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank You! I have 1 more :)

  42. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.